


Angels And Winchesters

by Ironkhaleesi



Series: Little Sister!Reader Incest - Marvel/Supernatural/Sherlock/Vikings/The Originals/Game of Thrones/Teen Wolf/King Arthur: Legend of the Sword [7]
Category: Supernatural
Genre: F/M, Incest, Reader Insert, Smut, older brother/little sister incest
Language: English
Status: Completed
Published: 2017-05-06
Updated: 2017-05-06
Packaged: 2018-10-28 17:59:55
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,346
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10836450
Author URL: https://archiveofourown.org/users/Ironkhaleesi/pseuds/Ironkhaleesi
Summary: The Winchester’s have always had a thing for Castiel’s little sister, but when Dean takes it too far one day, they soon find out that so does Castiel.





	Angels And Winchesters

When Dean asked Cas about his little sister, the angel should have known what was going on immediately. Of course, it wasn’t all Dean’s fault. Miscommunication is all it was. Technically, all angels were related. They all called each other brother and sister. But you were different.

You were always different.

You and Cas grew up together. You’d been attached at the hip for thousands of years. No one could ever work out why the two of you were closer than other angels. It could have been because Cas had always been charged with looking after you.

It was only natural that he developed the feelings and over protectiveness of any other older brother. What wasn’t natural were the other feelings that came later.

It was uncommon for angels to have romantic or sexual feelings for one another. They just weren’t built like humans. But Cas had always been different.

The other angels always said he had a screw loose. He was too susceptible to human emotions. You were just as bad – if not worse. In fact, you openly embraced your flaw.

Cas had more trouble keeping you in heaven away from the humans. You were always sneaking away, coercing with them. Learning their ways, feeling what they felt.

Hanging around the Winchester’s was a gold mine for you. You were always asking them questions. Asking them why they felt a certain way. Why they didn’t express their feelings at certain times.

At first, Cas could see their discomfort. On multiple occasions, Sam had avoided you and Dean had asked Cas to get rid of you. But you always found your way back. Partly because nothing could stop you from getting what you wanted. And partly because Cas didn’t like being away from you.

Over time the brothers became used to your nosiness. They even welcomed it. That’s when Cas started feeling uncomfortable.

Sam would often hide away with you and speak to you for hours. You were a good listener. You tried to understand. And you didn’t judge, nor did you spill his secrets. Sam became fond of you. Started doing little things for you. Making you meals (not that you could really eat them). Going out of his way to help you understand human life and the little things that mattered.

As Sam’s affection grew, so did Cas’s anxiety. Thankfully, Sam never took it further, he could see that Cas wasn’t okay with it.

Dean was a different story. He was oblivious to the differences between Cas’s bond with you compared to other angels. He was oblivious to the feelings that Cas had tried hiding for thousands of years.

And, of course, there was nothing Cas could do when Dean showed interest in you because you lapped it up like a child in a classroom. Dean could teach you about the very things that fascinated you the most about humans.

Sex. Intimacy. Flirtation. Pleasure.

At first, you’d tried to ask Sam about those things because he said he considered you a friend. In your mind, friends could talk about those kinds of things. Cas knew Sam wanted to teach you, but he also knew he’d worked out how Cas felt about you.

So, Dean it was. Oblivious-Dean. One-track-minded-Dean. Do-anything-to-make-Cas’s-beautiful-little-sister-cum-Dean. 

Cas’s jaw ticked as he heard Dean’s deep laugh. He was sitting at the end of one of the library tables with Sam sitting perpendicular to him reading a book. Dean was at the other end of the table. He’d pulled his chair around to sit next to you.

You were both doing something on his laptop. And with the headphones out and the way Dean’s body fidgeted and tensed as he whispered in your ear – the way your eyes were glued to the screen and your chest rose and fell with quickened breaths – Cas knew Dean was showing you porn.

 

You looked up at Dean and said something, probably asked a question. Dean chuckled again and leaned forward to whisper the answer in your ear. Your brows rose and Dean pulled back to gauge your reaction.

He said something else then. Something like, “I’ll show you.” Then he was leaning in once more, this time to press his lips to your neck in a butterfly kiss. He kissed you again, higher up, a little firmer, a little more open-mouthed. Then again, higher, his tongue swiped over your pulse.

Your eyes went hooded and you tilted your head to the side. Your lips parted and Cas could feel your sigh of pleasure like a knife in the gut.

Cas slammed his hands down on the table. Everyone jumped in shock and looked at him. His chair screeched against the wooden floor as he pushed it back and stood.

His eyes stayed locked on Dean as he marched to the end of the table and slammed the laptop closed.

“What the hell, Cas?” Dean said as he pulled his earphone out.

You pulled your own out, too, before standing and placing a hand on Cas’s arm.

“Is everything alright?” you said.

Cas couldn’t bear to see the concern in your eyes so he kept his glare on Dean.

“Stay away from Y/N,” Cas growled.

Dean’s brow furrowed. “Uh … what?”

“She is not for you to fool around with and throw to the side when you’re done. You aren’t who I want her to be with. And you don’t get to teach her about these things.”

Dean was too shocked and offended to say anything. Sam opened his mouth to pitch in but closed it when Cas narrowed his eyes at him.

“We’re leaving,” Cas said when no one opposed him.

He didn’t look at you, afraid you’d melt away his anger and make him see reason. He just took a gentle hold on your arm and transported the two of you far away. To a bedroom up in heaven.

“Castiel,” you said. And just your voice had him calming down and looking up through his lashes at you in embarrassment. “Is everything alright?”

“Yes … no.”

You moved forward and pressed a hand against his chest, right over his heart. He looked down at it, marvelled at how much a simple touch could make him feel. He raised his eyes back up to your face. You gave him a gentle smile.

“Then tell me what’s wrong. I can help,” you said.

Cas didn’t know if it was what you said or how you looked at him. It could have been your hand against his heart or a combination of all three.

Or, maybe, it was the thousands of years he’d spent running from everything you made him feel.

Whatever it was, in that moment, the way you looked at him so openly, it was the drop that overflowed the bucket.

Without warning, he cupped your face in his hands and pressed his lips to yours. You froze for a moment, but when you didn’t push him away, he moved his body in close enough that your hand was trapped between the two of you.

You hesitated a moment before you tilted your head to the side and leaned into him.

The nerves that churned Cas’s stomach eased with your acceptance, but the moment his tongue snaked forward to brush against your lips, you pulled away and the nerves were back again.

“I’m sorry,” he said. “I should have … I shouldn’t –”

 

“It’s okay, Castiel,” you said as you lifted your fingers to your lips. “It’s just … I don’t know what I’m doing.”

“I’ll teach you,” he said with a little more haste than he intended. “I mean … I can show you. I know a little.”

“How?”

“From Dean, mostly. I used to ask him questions, but then he just made me watch porn. I don’t think it’s accurate, though. I mean, I’ve only had sex once but … well, she killed me afterward. The pizza man didn’t do that.”

Your lips stretched into a shy grin and you nodded. “Okay.”

“Okay?”

“You can show me. I’ve never thought of being with another angel before. I’m not sure it’s even allowed. But … you’re – you’re my Castiel. Right?”

Cas smiled and nodded once. “Right.”

 

“So …” you stepped closer to him, “where do we start?”

“I think, uh, I think we remove our clothes.”

So, that’s what the two of you did. Cas’s trench coat went and so did your shirt. By the time he had his tie on the floor and his shirt unbuttoned, you were starting on your pants.

Cas looked up at you and his hands froze at his belt buckle when he saw your naked torso.

Your pants went next, and you looked up as you slid them down your legs.

“Are you okay, Castiel?” you said. He said nothing as you straightened. His stomach was churning with butterflies again but it wasn’t nerves this time. “Do you need help?”

You moved forward without waiting for an answer and pushed his hands away from his belt buckle.

“I think,” you said as you undid the buckle and slid the belt through the loops of his pants, “that I prefer to undress you myself.”

You lifted your hands to his torso and ran them over his skin as you pushed his shirt open and off his shoulders. You chased the shirt down his arms, rubbed your fingers against his palms.

His nose bumped against yours affectionately as he watched your face. Of all his experience, he never thought he could feel such intimacy in this moment. Such a need to hold and stroke.

He’d always seen sex as a frenzy of hungry bodies, and he supposed he had that animalistic feeling in his chest, but for right now … he wanted things to go slow. He wanted to memorise you. To touch every inch of your skin and maybe kiss it too.

Yeah, definitely kiss it.

You looked up and smiled as your fingers trailed back down his stomach to play along the top of his pants. As you undid them, you pressed your lips to his, this time taking the initiative and running your tongue along his lip.

He responded by opening his mouth and sliding his tongue against yours. His breath came a little heavier and you let out a small sound.

Suddenly, he felt the air against his hips, and you were pulling away to push his pants and boxers down his legs.

“Can I touch you?” Cas said as he stepped out of his clothes.

You gave him a confused smile. “Yes …”

“Uh, Dean said I should always ask before I touch a naked person.”

“Oh.” You chewed on your bottom lip. “So, am – am I allowed to touch you?”

Cas smiled. “Of course.”

Your hands were back against his skin. Cas forgot that he’d wanted to touch you for a moment, too absorbed with the tingling sensation your fingers left behind.

“I like this vessel,” you said as you dragged your hands down lower. “It’s so … responsive.”

Cas sucked in a breath when your fingers danced around his erection – not quite touching anything, but close enough that he had the urge to thrust his hips forward.

You pulled your hands away, a shy look in your eye, and Cas remembered that you weren’t sure what to do. That you didn’t know where to go next.

He lifted his hands to your waist and pulled you in closer to his body. He pressed his lips against yours again, but only briefly. As he pulled back, he slid his hands up over your ribs to cup the underside of your breasts.

You sucked in a breath. Cas hesitated for a moment, but a quick glance at your face reassured him enough to keep going. He slid his hands up a little further, brushing his thumbs over your nipples before kneading your breasts.

Your chest rose with your quickening breaths.

“This is different,” you breathed.

“What?”

“When Dean touches me … it’s different. This feels better.”

There was something visceral in that comment. Something that brought out an alpha male type of satisfaction in Cas.

“Good,” he growled, then his mouth was on yours again and his hands were dropping to your hips to yank down the material of your underwear.

All urges to go slow and savour the moment disappeared with the revelation that you wanted him more than you wanted Dean. Now he just wanted to claim you. Mark you up so there was physical evidence for Dean to see.

You fell onto the bed with a bounce when Cas pushed you towards it. For a moment, he stopped and thought about whether he was moving too fast for you, but then you were pulling him down on top of you and all doubt was gone.

The first mark he left was at the top of your right breast. The next ones were scattered across your stomach and inner thighs. Your neck got the worst of it – a long, dark line of marks starting from the bottom of your ear and leading right down to your collarbone.

Once he was happy with his work, he began leaving a trail of kisses down your stomach, relishing in the noises you made and the way you writhed beneath him.

When he pressed his lips to the front of your mound you let out a nervous squeak.

“What are you doing, Castiel?” you said.

“Something Dean said I should try.”

Without waiting for an affirmative, he dove down and ran his tongue through your folds. From what Dean had told him, he’d expected you to feel pleasure, but he hadn’t been prepared for the throaty moan and the way you suddenly gripped his hair in your fingers.

He did it again, and this time he didn’t stop. It took a moment, but eventually, he worked out it was better to let you roll your hips against his tongue and go wherever you moved him. And the more you pulled his hair, the more pleasure you were feeling.

It was painful at times but it was worth it to look up and see your head being thrown back into the pillow and your mouth falling open on the kind of sounds he’d only heard in the pornos.

Cas almost got lost in just the act itself, almost forgot that he was building up to something, and was just enjoying the moment when a particularly high-pitched moan fell from your lips.

“Castiel … I’m … something’s happening,” you panted.

He didn’t have to think hard to figure it out. It was another thing that Dean had talked to him about. You were about to climax, or ‘cum’ as Dean was rather fond of calling it.

Cas kept his tongue in place but sucked and licked your flesh faster. He also held your hips down this time. Dean said that not holding a woman down while she came on his tongue was the easiest way to break a nose or chip a tooth.

Cas realised the truth in that when your orgasm hit and it took all his strength to hold your hips down. And he was sure you’d ripped out chunks of his hair. But he would never forget the way you cried out his name and arched your back off the bed.

 

He would never forget how you tasted, and the feeling of your contractions on his tongue as he licked you clean.

You were giggling and stretching out beneath him as he crawled back up your body.

“That was … can we do it again?” you said with a blissful look.

Cas smiled. “Yes. But, I think you’re supposed to wait a little while.”

You pouted and pulled him in tighter so he was resting on his forearms and his body was flush against yours. “Why? I don’t want to wait.”

Cas chuckled. “Your body is too sensitive.”

You ran your fingers through his hair. “I don’t feel sensitive.”

Cas raised his brows at your insistence but decided showing you was easier. He slid a hand between your bodies and smoothed his fingers over your wet clit. You let a squeak of disapproval and slapped at his shoulder.

He chuckled again and brought his hand back up. You sighed in disappointment.

“So, we can’t do anything now?” you said.

“No, there’s – there’s other stuff we can do.”

“Like what?”

Cas thought for a moment before he began shifting above you. “Spread your legs,” he said. 

You did as he asked and he settled back down between them. He took a moment to enjoy the feeling of your thighs pressed against his hips, then he was hooking his hand behind one of your knees and pulling it up against his ribs.

He slid his hand back between your bodies and lined himself up. You sucked in a breath and Cas let out a deep moan as he slid into you. You dug your nails into his ass and brought your other knee up against his ribs.

“Castiel,” you breathed.

“Are you okay?” he said once he was completely inside you. His voice more gravelly than usual.

“Yes,” you groaned. “Please, Castiel.”

He knew you didn’t know what you were begging for – that the feeling of having him inside you after you’d orgasmed was intense.

So, he did the only thing he could. He pressed his lips against yours in a searing kiss that didn’t stop as he began rolling his hips against yours. You moaned into each other’s mouths. Locking lips when you could and breathing in each other’s panted breaths when you couldn’t.

 

He slid his arms under your body and squeezed you to him so there wasn’t one inch of your bodies that weren’t touching.

You tilted your head back into the pillow and Cas moved his mouth down to your throat.

 

“More, Castiel,” you groaned.

Cas wasn’t sure what more he could do – there was only so much he’d been able to learn – but he did what Dean said, and acted instinctually.

He pushed into you until his pelvis was pressed against your and his balls were coated in your slick. His thrusts were short, then. Just enough to grind into you.

You cried out and your head came up off the pillow. “Yes! Cas – Cas – Cas …” Your head fell back again, your brows furrowed and your eyes squeezed shut.

You went silent and Cas frowned in confusion. Then he felt it. A moan was ripped from his throat as you tightened around him. He began thrusting harder and faster, chasing his own pleasure as you convulsed around him in a way he’d never felt before.

Finally, a high-pitched moan fell from your lips and you slapped your hands down on Cas’s shoulders, scratching and clinging to him as he fucked you through the aftermath of your orgasm.

He became desperate as he climbed to his own peak. He buried his face in your neck and pulled your leg up impossibly higher as he moaned and panted against your skin.

 

His thrusts became irregular and he growled as you nipped at the skin of his neck.

When he finished and rolled to his back next to you, he almost couldn’t believe any of it had happened. Thousands of years spent watching you, chasing you, protecting you, and it had all lead to this one, blissful moment.

The two of you laid there, panting and staring up at the ceiling. Neither of you knew what to say, or at least, Cas didn’t know what to say. He wasn’t even sure what you were thinking.

“I think I’m in love with you,” you said, and Cas’s entire world froze.

“What?” he breathed.

“I mean … I – I don’t know. Sam explained it to me and … and I think that’s how I feel.” Cas couldn’t drag his eyes away from the ceiling. He was finding it hard to breathe and his eyes were burning with tears that he rarely shed. You turned your head to look at him. “Say something.”

“I know I love you,” he said. He looked at you. “I’ve always known.”

**Author's Note:**

> I've got more fics at iavengesuperwholock.tumblr.com


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